Highlights. Gender differences in toy choice exist and appear to be the product of both innate and social forces.. Despite methodological variation in the choice and number of toys offered, context of testing, and age of child, the consistency in finding sex differences in children's preferences for toys typed to their own gender indicates the strength of this phenomenon and the likelihood that has a biological origin.. The time playing with male-typed toys increased as boys got older, but the same pattern was not found in girls; this indicates that stereotypical social effects may persist longer for boys or that there is a stronger biological predisposition for certain play styles in boys.

Abstract: From an early age, most children choose to play with toys typed to their own gender. In order to identify variables that predict toy preference, we conducted a meta-analysis of observational studies of the free selection of toys by boys and girls aged between 1 and 8 years. From an initial pool of 1788 papers, 16 studies (787 boys and 813 girls) met our inclusion criteria. We found that boys played with male-typed toys more than girls did (Cohen's d = 1.03, p < .0001) and girls played with female-typed toys more than boys did (Cohen's d = −0.91, p < .0001). Meta-regression showed no significant effect of presence of an adult, study context, geographical location of the study, publication date, child's age, or the inclusion of gender-neutral toys. However, further analysis of data for boys and girls separately revealed that older boys played more with male-typed toys relative to female-typed toys than did younger boys (β = .68, p < .0001). Additionally, an effect of the length of time since study publication was found: girls played more with female-typed toys in earlier studies than in later studies (β = .70, p < .0001), whereas boys played more with male-typed toys (β = .46, p < .05) in earlier studies than in more recent studies. Boys also played with male-typed toys less when observed in the home than in a laboratory (β = −.46, p < .05). Findings are discussed in terms of possible contributions of environmental influences and age-related changes in boys' and girls' toy preferences.

ABSTRACT: The sex difference in jealousy is an effect that has generated significant controversy in the academic literature (resulting in two meta-analyses that reached different conclusions on the presence or absence of the effect). In this study, we had a team of researchers from different theoretical perspectives use identical protocols to test whether the sex difference in jealousy would occur across many different samples (while testing whether mate value would moderate the effect). In our samples, we found the sex difference in jealousy to occur using both forced choice and continuous measures, this effect appeared in several different settings, and, we found that mate value moderated participant responses. The results are discussed in light of the controversy surrounding the presence of the effect.

Abstract: Physical cues influence social judgments of others. For example, shorter individuals are evaluated less positively than taller individuals. Here, we demonstrate that height also impacts one of the most consequential intergroup judgments—attributions of humanity—and explore whether this effect is modulated by the tendency to value hierarchy maintenance. In Study 1, the shorter participants perceived a range of out-groups to be, the more they dehumanized them, and this tended to be particularly pronounced among those scoring high on social dominance orientation (SDO). In Study 2, participants dehumanized an out-group more when they were led to believe that it was relatively short. Finally, Study 3 applied a reverse correlation approach, demonstrating that participants in general, and especially those scoring high on SDO, represented shorter groups in ways less consistent with full humanity than they represented taller groups. Together, this research demonstrates that basic physical height cues shape the perceived humanity of out-groups.